electromagnetism

The science of electricity and
magnetism; specifically, the study
of electric and magnetic
fields. The two fields are in fact different manifestations of the
same physical field, and are interconverted according to the speed of
the observer. The theory of electromagnetism, including light,
was first developed by Michael Faraday
and James Clerk Maxwell in the 19th
century. See also Maxwell's equation.

One of the four fundamental forces of nature along with gravity,
the weak force, and the strong
force. It is the interaction due to electric charge, which also
includes magnetic effects that have to do with moving electric charges.
Electromagnetism is the second strongest force after the strong force.
At the quantum level it is mediated by photons,
and is well described by the theory of quantum
electrodynamics.